Basically I can see a few things here:

1. It's unhealthy to not have your fellow girlfriends. It's unhealthy for us guys to not have our boys.

2. Space is important. If you keep nagging him to spend time while he's hanging out with his friend, you are going to get the same response. Most guys don't respond well to nagging.

3. What does this exactly have to do with pot? You keep leaning on it as an excuse you use and he uses.

If this guy can't live without some weed for a few hours to spend time with someone he loves, he's a g'damn loser. Do you want to be with a loser? Didn't think so.

From the sounds of it, he'll never get his business started. Yeah, starting a business requires discussion, and deep thought, but smoking pot while trying to plan it? Inexcusable.

Dump the SOB.